Philip francis oddie



No. 624,854. Patentad May 9, I899.

' P. F. ODBIE.

DUPLEX DIBE GTAGTING PUMPING APPARATUS.

(Application flied Sept. 28, 1688.) (No Model.) 2 Shasta-Sheet l.

"0.624354. raiaht eu Ma s, lass.

P. F. onnlE. DUPLEX DIRECT ACTING PUMPING APPARATUS.

(Application filed Sept. 29, 1898.)

(No Model.) 2 sham-sum 2.

g /llllllll/lzj NI'IED STATES PATENT" OFFICE.

PHILIP FRANCIS ODDIE, OF LONDON, ENGLAND ASSIGNOR TO TI-IE ODDESSE DAMPFPUMPEN GESELLSOIIAFT MIT BESCHRANKTER HAFTUNG, OF HAM- BURG, GERMANY.

DUPLEX DIRECT-ACTING PUMPING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 624,854, dated May 9, 1899.

Application filed septemher 23, 1898. erial No. 691,747. (No model.)

To all whom it may concern:

Be it known that I, PHILIP FRANCIS ODDIE, engineer, a subject of the Queen of Great Britain, residing at 9 Mansel road, Wimbledon, London, in the county of Surrey, England, have invented certain new and useful Improvements in Duplex Direct- Acting Pumping Apparatus, (for which an application for patent has been filed in Great Britain March 1, 1898, No. 5,022, and in Germany April, 1898,) of which the following is a speci- V fication.

This invention relates to improvements in duplex direct-acting pumping apparatus, and

is designed to enable such pumps to be worked by means of steam used expansively '-that is to say, to enable the supply of steam to the piston-cylinders to be out off considerably before those pistons have completed their respective strokes, instead of the supply of steam, as is ordinarily the practice, being c0ntinued substantially to the end of each stroke.

In carrying out my invention I provide at the water end or part of the pump-chamber behind each plunger a separate or extra chamber, into which a prolongation or plunger extension from the end of the main pump- -plunger enters through suitable bushing or packing, and the extra chamber of the one- (duplex) pump or main chamber is in com munication with the rear or back end of the other pump or main chamber, while the extra chamber of the other pump or main chamber is in communication with the opposite main chamber. No additional valves are required to enable the parts to operate, and other parts are substantially as usual.

' In the drawings, Figure 1 represents a longitudinal section, and Fig. 2 a sectional plan, of the water end of a duplex pump arranged to carry out my invention; Figs. 3, 4, 5, and 6, by four views in sectional plan, the sequence of motions performed by the steampistons and auxiliary or compensating plungers, so as to facilitate acorrect comprehension of the cycle of movements performed.

during one complete reciprocation of'the cooperating parts, as shown in'the drawings.

Behindeach pump-cylinder (marked I and able bushes or packing a 19 into the auxiliary I chambers a 19 The auxiliary chamber a of the one pump I is connected by means of a channel a with the backend b of the other pump II, while the auxiliary chamber 19 of the pump II is connected by a channel b with the opposite end a of cylinder I. Thus' no additional gear or valves are required and only those ordinarily in use are needed.

The steam enters either the steam-cylinder A or B and drives thepiston A or B and piston-rod and with itsets in motion the pumpplunger A or B corresponding and an auxiliary plunger a or 5 l The steam can be cut off at a suitable point, either fixedor variablefor example, twothirds of its stroke. In the ordinary construction the pump-pistons A must come to rest as soon as the steam is cut off, as the effective steam-pressure is not strong enough to overcome the water-pressure in the pump. In the present invention, onthe other hand, the main piston of the one is relieved at this moment by the motion of the auxiliary piston in the other.

In operation, referring to Fig. 4, the steam being admitted to what for the sake of distinction Iwill call steam-cylinder A, operating the steam-piston A and rod or connection to operate its coacting plunger A in the main pump portion in the direction of the arrow 1, such steammay be out off at a con-.

upon steam being cut off come to rest at the point shown in Fig. 5 on account of the eifective steam-pressure becoming insufficient to overcome the water-pressure.

In duplex pumping apparatus arranged ac cording to my invention while the steam-piston A is acting upon the main plunger A to pump water the plunger-extension a in its extra chamber a is meanwhile also forcing water therefrom into the pump-valve chamber 1) behind main plunger B until the steam-piston A has reached two-thirds of its entire stroke and the pump-plunger A the same extent. Then main plunger B as already referred to and shown-in Fig. 5, being operated by steam-piston B and its connection, commences its return motion in its pump-cylinder II, and in doing so the pressure in rear thereof being relieved the pressure in the extra chamber a partakes of that relief, facilitating the completion by ,plunger A of its stroke.

When the steam supplying pressure to piston B is cut off upon it and its coacting main plunger 13 having completed their strokes to the extent of two-thirds the full stroke, aposition indicated by Fig. 6, cut-off is effected and the stoppage of its stroke is prevented by the main plunger A starting on its return stroke under the operation of its own steampiston A and communicating the pressure of the water at its front end to the extra chamber 11 and additional plunger 19 provided in like manner to the rear end of the main plunger B the water-pressure passing by channel 12 thereby assisting that plunger 13 in its completion of the stroke. Then, referring to Fig. 3, the piston A in the cylinder A continues its motion in the direction of the arrow 7, the steam is cut off, and the piston 13 commences its return motion in the direction of arrow 8. Until the piston A reaches the position shown in this figure-about two-thirds of its strokethe main plunger A has been forcing water through the delivery-valve of the pump, exercising the full area of its surface, and has at the opposite faces A of its main plunger and reduced face a of the auxiliary plunger been drawing water through the suction-valves, the combined areas of these two faces A and 0. equaling approximately the area of the opposite face A As soon as the piston A has reached the position indicated in this figure the piston B commences its traverse in the direction of arrow 8, and consequently the plunger B and auxiliary plunger b partake of the same motion. The motion of the plunger 13 by its rear face B pressing on the water in b communicates that pressure through channel a to the auxiliary chamber a in rear of auxiliary plunger a and presseson the face a of that auxiliary plunger, assisting the piston A to complete the stroke. As soon as this has been accomplished the piston B, (see Fig. 4,) still moving in the direction of the arrow 2, arrives at the point where its steam-supply is cut off and piston A is about commencing its return traverse in the direction of arrow 1, and doing so, the water-pressure in front of plunger A being relieved, that relief of pressure is by the channel b communicated to the chamber 5 in rear of the auxiliary plunger b and thereby the completion of the stroke of piston 13' is assisted, and so on the cycle of operations is continued repeatedly, thereby constituting a compensating arrangement by which the excess of pressure at the commencement of the stroke of the one steam-piston, as A, is through its coactin g plunger, as B utilized in aid of the deficiency of steam-pressure existing toward the end of the stroke of the opposite steam-piston, and so on. 7

Although I have referred to two-thirdscutoff, this extent of cut-off may be varied. Again, I have for illustration described the extra chambers as being arranged in rear of the main plungers and chambers; but they may be arranged in other relative positions, as may be found most convenient under particular circumstances, and the extra or extension pump-plungers will be arranged in accordance with the change of position of their chambers. Such an arrangement of plungers and auxiliary plungers and their chambers may be conveniently used with arrangements of steam-cylinders used in what are known as the compound type of duplex pumping-engines.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that What I claim is 1. In a duplex pumping-engine the combi* nation with the two steam-actuated pistons, as A and B, and their connected plungers A and B of auxiliary plungers as a 19*, respectively, auxiliary chambers therefor and Water-passages a and b connecting the spaces between the suction and delivery valves of the main plungers with the opposite chambers in rear of the auxiliary plungers respectively, substantially as shown and described.

2. In a duplex pumping-engine, a pair of main steam pistons and cylinders and connected main plungers and cylinders, an aux- .iliary plunger connected to the one face of one of the said main plungers, an auxiliary chamber in rear thereof, a connecting-channel connecting said auxiliary chamber with the space in rear of the other of the said main plungers, a second auxiliary plunger connected with the other main plunger, a second auxiliary chamber therefor and a second connectin g-channel connecting said second auxiliary chamber with the chamber of the first-mentioned main plunger, as set forth.

3. In a duplex pumping-engine, steam-pistons A and B, cooperating main plungers A B auxiliary plungers CR, 19 and cylinders for the same to reciprocate in, in combination with pressure-relieving passages connecting, respectively, the cylinder of one auxiliary plunger of one pump with the cylinder of a main plunger of the otherpump, and arranged as described, whereby to permit the one plunger to operate in relief of the other my hand in presence of two subscribing Witplunger toward the end of the stroke of the nesses. latter to enable said latter plunger to complete its stroke by the expansion of steam PHILIP FRANCIS ODDIE 5 after steanrpressure thereto has been cut off, Witnesses:

substantially as described. ALFRED GEORGE BROOKES,

In testimony whereof I have hereunto set ERNEST JOHN HILL. 

